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In the Czech Republic, the scarce fritillary (Euphydryas maturna) had been considered extinct until the rediscovery of an extant population in Domanovický les, Central Bohemia. Subsequent efforts to protect the locality were thwarted by disputes between landowners and researchers. In 2010, when the population size was reaching critically low levels, appropriate management was finally established at the locality. To evaluate the current status of the population, an intensive mark-release-recapture study was conducted in the area in 2016 and 2017, comprising several hundreds captured individuals. The total population size was estimated at 764 butterflies for 2016 and 518 butterflies for 2017. In comparison with the pilot study performed in 2002, the population size was slightly higher, but the dispersal rates were lower. These results indicate that Euphydryas maturna in the Czech Republic has managed to bounce back from a critical population size. On the other hand, the risk of extinction has not been averted due to continued habitat loss and stochastic environmental effects. Management efforts should aim to expand the habitats used by the breeding populations, at present predominantly confined to temporary forest clearings and to open canopy forest with low tree density. Moreover, assisted reintroductions of this only surviving population to the surrounding areas should be considered.

The monitoring of sympatrically occurring Phengaris teleius and P. nausithous metapopulations in the surroundings of Přelouc, Czech Republic, was launched over a decade ago in connection with the planned waterway construction on the Elbe river. The mark-recapture surveys were initially restricted to 10 habitat patches on the right river bank, but in 2010 three new patches were discovered on the opposite bank. We use the monitoring results for 2011–2015 to assess how the discovery of additional populations alters the impact evaluation of the prospective construction. The overall abundance of P. teleius in the recently discovered populations was about twice as high as on the right bank (ca. 2,800 vs. 1,400 adults on average), while the numbers of P. nausithous on both banks proved to be balanced (at ca. 600 adults on average). Furthermore, we confirmed a substantial exchange of butterflies between population representing both banks, which indicates a well-integrated metapopulation in both species. Since the waterway would partly destroy the two largest populations on the right bank, the potential loss due to its construction is estimated at 40.1–64.3% P. teleius individuals and 20.2–47.4% P. nausithous individuals occurring there. Nevertheless, concerning the entire metapopulation, the predicted decline is considerably smaller, reaching 13.9–25.7% in P. teleius and 8.5–20.0% in P. nausithous. Consequently, a long-term survival of the species is likely even in the case of the waterway construction, as long as appropriate management is applied on the unaffected habitat patches.

Metapopulation models typically assume that suitable habitats occupied by local populations and unsuitable matrix separating them form a 'black- and-white' landscape mosaic, in which dispersal is primarily determined by the spatial configuration of habitat patches. In reality, however, the matrix com- position is also likely to influence dispersal. Using intensive mark-recapture surveys we investigated inter-patch movements in Maculinea (Phengaris) nausithous and M. teleius occurring sympatrically in six metapopulations. Three of these metapopulations had the matrix dominated by forest, an inhospitable environment for grassland butterflies, whereas in the remaining three the matrix was mostly composed of open environments. Dispersal parameters derived with the Virtual Migration model revealed significant differences between both groups of metapopulations. Both species had a lower propensity to emigrate from their natal habitat patches, and they suffered substan- tially higher dispersal mortality in the metapopula- tions with forest matrix. On the other hand, mean dispersal distances were roughly an order of magni- tude longer in forest matrix as compared with open landscapes (ca. 500-1,500 vs. 100-200 m). Our results suggest that inhospitable forest matrix induces strong selection against dispersal, leading to a reduced emigration rate. At the same time, the selection may promote emigrants with good dispersal abilities, which are able to perform long-distance movements. Thus, while it is generally believed that a matrix

A positive effect of (meta)population density on emigration has been predicted by many theoretical models and confirmed empirically in various organisms. However, in butterflies, the most popular species for dispersal studies, the evidence for its existence has so far been equivocal, with negative relationships between density and emigration being reported more frequently. We analysed dispersal in sympatric metapopulations of two Maculinea butterflies, intensively surveyed with mark–release–recapture methods for 7 years. Dispersal parameters, derived using the virtual migration model, were assessed against butterfly densities, which fluctuated strongly over the study period. Emigration was positively correlated with density, and this effect was particularly strong at densities above carrying capacity, when emigration increased up to threefold in females and twofold in males compared with the normal levels. In turn, density had little impact on other dispersal parameters analysed. Our findings provide good evidence for positive density-dependence of emigration in butterflies. Emigrating at high densities is particularly beneficial for females, because it gives them a chance to lay part of their egg-load in less crowded patches, where offspring survival is higher due to lower intraspecific competition. Even though the rise in emigration becomes considerable at densities exceeding carrying capacity, i.e. relatively infrequently, it still has serious implications for many ecological phenomena, such as species range expansions, gene flow, and metapopulation persistence. Consequently, instead of treating emigration as a fixed trait, it is worth allowing for its density-dependence in applications such as population viability analyses, genetic models or metapopulation models. Electronic supplementary material The online version of this article (doi:10.1007/s00442-011-2025-x) contains supplementary material, which is available to authorized users.

Recent land use changes, namely the intensification of agriculture and forestry as well as the abandonment of traditional grassland management methods, have resulted in the decline of butterfly diversity in Europe. Appropriate management of butterfly habitats is thus required in order to reverse this negative trend. The aim of our study was to review the available literary information concerning the effects of various types of management on European butterflies of conservation concern, and to provide practical recommendations for the management of butterfly habitats. Since vegetation succession is a major threat to butterfly populations, there is a need for activities to suppress this process. Extensive grazing and rotational mowing, which imitate the traditional way of meadow use, appear to be the most suitable management in this respect. Both grazing and mowing should optimally be of low intensity and follow a mosaic design, with different land fragments being successively used at different times. Habitat disturbance through trampling, either associated with grazing or various sporting activities (hiking, biking, horse riding), or through occasional small-area burning, also prove to be beneficial for many butterflies. In the case of woodland species, maintaining open habitats within forests (glades, clearings, wide road verges) and thinning forest stands is recommended. Among the unfavourable management activities identified, the most harmful are afforestation of open lands and drainage works. Therefore, such activities must be stopped at butterfly sites in order to ensure the effective conservation of species of conservation concern.

In most metapopulation models dispersal is assumed to be a fixed species-specific trait, but in reality dispersal abilities are highly sensitive to various selective pressures. Strict isolation of a metapopulation, which precludes any influx of immigrants (and their genes) from outside and makes it impossible for emigrants to reach other localities with suitable habitat, thus reducing fitness benefits of long-distance dispersal to zero, may be expected to impose strong selection against dispersal. We tested the above prediction by comparing dispersal parameters derived with the Virtual Migration model for isolated and non-isolated metapopulations of two species of large blue Maculinea (= Phengaris) butterflies, surveyed with intensive mark-recapture. Mortality during dispersal was found to be twice (in M. teleius) to five times higher (in M. arion) in isolated metapopulations. Isolation also resulted in significantly reduced dispersal distances in isolated metapopulations, with the effect being particularly strong in M. arion females. Apart from its evolutionary and ecological consequences, dispersal depression in isolated butterfly metapopulations implied by our results has serious conservation implications. It provides a clear argument against using parameter values obtained in a different environmental setting in modelling applications, e.g., Population Viability Analyses or environmental impact assessment. Furthermore, it underlines the importance of establishing well-connected networks of suitable habitats prior to species release in areas where reintroductions are planned.